Dependence on solar elevation and the daily sunshine fraction of the correlation between monthly-average-hourly diffuse and global radiation

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Solar Energy (Journal of Solar Energy Science and Engineering); (United States)

DOI:https://doi.org/10.1016/0038-092X(92)90094-Q· OSTI ID:5216155

Soler, A ^[1]

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1. E.T.S. Arquitectura, Madrid (Spain)

In the present work the authors study for Uccle, Belgium data (50{degree}48 minutes N, 4{degree}21 minutes E), the dependence on {anti {gamma}} and {sigma} of the correlations between {anti K}{sub d} = {anti I}{sub d}/{anti I}{sub o} and {anti I}{sub t} = {anti I}/{anti I}{sub o}, where {anti I}, {anti I}{sub d}, and {anti I}{sub o} are respectively, the monthly-average-hourly value of global, diffuse, and extraterrestrial radiation (all of them on a horizontal surface), {anti {gamma}} is the solar elevation at midhour and {sigma} the daily sunshine fraction. The dependence on {sigma} is studied for different ranges of values, from {sigma} = 0 to {sigma} > 0.9. The dependence on {anti {gamma}} is studied for {anti {gamma}} = 5{degree}, 10{degree}, 15{degree}, 25{degree}-30{degree}; 35{degree}-40{degree}; 45{degree}-60{degree} ({delta}{anti {gamma}} = 5{degree}). Relating the dependence on {sigma}, for increasing values of {sigma}({sigma} {>=} 0), there is an increase in {anti K}{sub d} with the increase in {anti K}{sub t}. For 0.42 < {anti K}{sub t} < 0.52 a maximum is obtained for {anti K}{sub d}. After the maximum, as the skies become clearer, {anti K}{sub d} decreases as {anti K}{sub t} increases. Relating the dependence on {anti {gamma}}, for each range of values of {sigma} ({sigma} > 0.2), values of the slope for linear {anti K}{sub d} = f({anti K}{sub t}) correlations show a tendency to decrease as {anti {gamma}} increases. For each value of {anti {gamma}} the slopes of the linear {anti K}{sub d} = f({anti K}{sub t}) correlations tend to decrease when {sigma} increases.

• OSTI ID: 5216155
• Journal Information: Solar Energy (Journal of Solar Energy Science and Engineering); (United States), Vol. 48:4; ISSN 0038-092X
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
BELGIUM
SOLAR RADIATION
HOURLY VARIATIONS
MONTHLY VARIATIONS
CORRELATIONS
DIFFUSE SOLAR RADIATION
ORIENTATION
SOLAR FRACTION
SPAIN
SURFACES
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
EUROPE
RADIATIONS
SOLAR FLUX
STELLAR RADIATION
VARIATIONS
140100* - Solar Energy- Resources &amp; Availability
990200 - Mathematics &amp; Computers